Machining Time Estimate for 5axis Toolpaths

[mattdlr89]

I've just started generating some 5 axis toolpaths using the contour operation. I notice that the machine time estimate which is normally fairly accurate for me on 3 axis toolpaths is way off for 5 axis. It machines freely when I run it so I don't think the machine is limiting it, but I guess it could still be, I'm inexperienced with 5 axis machining. 

It estimates at 5 minutes but it is closer to 25 minutes actual machine time. Is this the same for everyone?

[dylan_smith]

Hi @mattdlr89,

I believe the toolpath time will not take the axis movement into consideration. The toolpath won't achieve the desired feedrate throughout the whole toolpath and Fusion doesn't take this into consideration. 

Its easier to calculate 3 axis as there is less variables involved. 

[ChristopherMarion]

Hi @mattdlr89 

@dylan_smith is spot on, it's hard for any CAM system to account for all machine movements for every type of machine.  A machine is only as fast as it's slowest axis and normally on a 5 axis mill, that is one of it's rotary axes.  Plus some controllers allow for different types of acceleration and decelerations in different situations.  That is something Fusion cannot anticipate.

It would be nice to have a time factor option.  I think ArtCAM had an option to put this in during simulation so you can at least adjust this time if you knew these toolpaths were say 25% slower that the actual calculated time in Fusion.

FeatureCAM also has options to adjust for toolchange times and rapid feeds.  Gives you a better idea of actual times on the machine.

Who knows, maybe we'll see this in Fusion some day 😉

[mattdlr89]

Thanks for the responses. 

I’m not sure I fully understand how the feed rates work on 5 axis. I did read up on inverse time feedrates when we got the machine a fair few years ago but can’t quite recall. If fusion is calculating the feedrates can it not make a good estimate at the time?

otherwise it is possible to  change the machining time by a factor but it applies the same factor to all toolpaths it would be good if I could set just 5 axis toolpaths to a certain factor to get a better estimate of times. 

[mathew.hutton]

@dylan_smith 

As @ChristopherMarion has pointed out, it would be good to have this functionality in Fusion so a user can define the speed of which their machines axes travel. Has a ticket been submitted for this yet? If not we should consider adding one as a new feature/ improvement

Mat